Semiconductor Thermal and Electrical Properties Decoupled by Localized Phonon Resonances (Adv. Mater. 26/2023)

Phonon‐Engineered Thermoelectricity In article 2209779, Mahmoud I. Hussein, Kris A. Bertness, and co‐workers demonstrate a reduction in the in‐plane thermal conductivity of semiconductor membranes by coupling heat‐carrying phonons to the localized phonon resonances emerging from deposited nanopillars. This full‐spectrum resonance–hybridization mechanism decouples the electrical and thermal properties, paving the way for novel thermoelectric materials. The experimental results are a manifestation of nanophononic metamaterial effects previously shown by theory and simulations.